---
title: "Tubing Size Chart: OD, ID and Working Pressure by Model"
canonical: "https://yuannaitube.com/tubing-size-chart/"
language: "en-US"
---

RESOURCES

# Tubing Size Chart: OD, ID and Working Pressure by Model

By  [YUANNAI TUBE](<https://yuannaitube.com/about/>) Published 2026-10-23Updated 2026-11-06

![Three tube sizes in order with a caliper measuring the largest](<https://yuannaitube.com/wp-content/uploads/2026/10/tubing-size-chart-cover-20261025-1024x683.webp>)

This **tubing size chart** lists every standard **pneumatic tubing size** and the **tubing dimensions** we manufacture, with model, outside diameter, inside diameter, **wall thickness**, **working pressure** and minimum **bend radius** for all eight material families. All figures come from our own published model tables — nothing here is generic industry data.

**Quick answer.** Standard **metric pneumatic tubing sizes** include 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, and 16 mm outside diameter (OD), paired with matching fractional imperial sizes (1/8″, 1/4″, 3/8″, 1/2″, and 3/4″) under shared model codes (0425 through 1612), with fractional sizes from 1/8″ to 1/2″ (plus 3/4″ on two families). Tolerance is ±0.10 mm on both diameters across every family. Find your size in the family table below, then confirm the **working pressure** at your **operating temperature** — the ratings differ by material at the same size.

## How to read the chart

Tubing is specified by outside diameter and inside diameter; the wall is the half-difference of the two, shown here rounded to two decimals. Fittings accept one specific OD-and-wall combination, so match the chart to the fitting seat rather than to a nominal name — the  [size and wall thickness guide](<https://yuannaitube.com/tubing-id-od-wall-thickness/>)  explains the conventions and includes a worked example.

Working pressures are the published ratings for each model. They hold at the stated reference temperature; the  [working pressure and temperature review](<https://yuannaitube.com/working-pressure-temperature-review/>)  covers derating before you use them on a hot line.

## PU Tubing sizes (15 models)

The standard polyurethane range: the tightest bend radii in the catalogue, rated 5–8 bar on metric sizes. Full details on the  [PU tubing page](<https://yuannaitube.com/products/pu-tubing/>) .

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-PU 0425 | 4.0 | 2.5 | 0.75 | 8 bar (128 psi) | 10 mm |
| YN-PU 0640 | 6.0 | 4.0 | 1 | 8 bar (128 psi) | 15 mm |
| YN-PU 0850 | 8.0 | 5.0 | 1.5 | 7 bar (116 psi) | 20 mm |
| YN-PU 0855 | 8.0 | 5.5 | 1.25 | 6 bar (99 psi) | 22 mm |
| YN-PU 0860 | 8.0 | 6.0 | 1 | 5 bar (75 psi) | 25 mm |
| YN-PU 1065 | 10.0 | 6.5 | 1.75 | 7 bar (106 psi) | 25 mm |
| YN-PU 1080 | 10.0 | 8.0 | 1 | 6 bar (94 psi) | 30 mm |
| YN-PU 1280 | 12.0 | 8.0 | 2 | 7 bar (104 psi) | 50 mm |
| YN-PU 1410 | 14.0 | 10.0 | 2 | 7 bar (106 psi) | 70 mm |
| YN-PU 1612 | 16.0 | 12.0 | 2 | 7 bar (109 psi) | 95 mm |
| 1/8 | 3.17 | 1.58 | 0.79 | 12 bar (174 psi) | 8 mm |
| 1/4 | 6.35 | 4.35 | 1 | 10 bar (145 psi) | 16 mm |
| 3/8 | 9.52 | 6.35 | 1.58 | 10 bar (145 psi) | 25 mm |
| 1/2 | 12.7 | 9.6 | 1.55 | 8 bar (116 psi) | 35 mm |
| 3/4 | 19.05 | 15.88 | 1.58 | 6 bar (87 psi) | 65 mm |

## Polyether Tubing sizes (14 models)

The polyether-TPU grade: same sizes and codes as PU, higher metric pressure ratings, the default for humid service. Full details on the  [Polyether tubing page](<https://yuannaitube.com/products/polyether-tubing/>) .

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-PUR 0425 | 4.0 | 2.5 | 0.75 | 10 bar (145 psi) | 15 mm |
| YN-PUR 0640 | 6.0 | 4.0 | 1 | 10 bar (145 psi) | 25 mm |
| YN-PUR 0850 | 8.0 | 5.0 | 1.5 | 12 bar (175 psi) | 30 mm |
| YN-PUR 0855 | 8.0 | 5.5 | 1.25 | 8 bar (116 psi) | 40 mm |
| YN-PUR 0860 | 8.0 | 6.0 | 1 | 8 bar (116 psi) | 40 mm |
| YN-PUR 1065 | 10.0 | 6.5 | 1.75 | 10 bar (145 psi) | 40 mm |
| YN-PUR 1080 | 10.0 | 8.0 | 1 | 8 bar (116 psi) | 45 mm |
| YN-PUR 1280 | 12.0 | 8.0 | 2 | 10 bar (145 psi) | 50 mm |
| YN-PUR 1410 | 14.0 | 10.0 | 2 | 10 bar (145 psi) | 70 mm |
| YN-PUR 1612 | 16.0 | 12.0 | 2 | 8 bar (116 psi) | 95 mm |
| 1/8″ | 3.18 | 1.7 | 0.74 | 12 bar (174 psi) | 8 mm |
| 1/4″ | 6.35 | 4.35 | 1 | 10 bar (145 psi) | 16 mm |
| 3/8″ | 9.52 | 6.35 | 1.58 | 10 bar (145 psi) | 25 mm |
| 1/2″ | 12.70 | 9.52 | 1.59 | 8 bar (116 psi) | 35 mm |

## PA6 Nylon Tubing sizes (14 models)

General-purpose nylon: the highest pressure ratings in the range on most sizes, at the cost of larger bend radii. Full details on the  [PA6 Nylon tubing page](<https://yuannaitube.com/products/pa6-nylon-tubing/>) .

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-PA6 0425 | 4.0 | 2.5 | 0.75 | 41 bar (592 psi) | 40 mm |
| YN-PA6 0640 | 6.0 | 4.0 | 1 | 35 bar (512 psi) | 35 mm |
| YN-PA6 0850 | 8.0 | 5.0 | 1.5 | 28 bar (412 psi) | 45 mm |
| YN-PA6 0855 | 8.0 | 5.5 | 1.25 | 28 bar (412 psi) | 47 mm |
| YN-PA6 0860 | 8.0 | 6.0 | 1 | 23 bar (341 psi) | 48 mm |
| YN-PA6 1065 | 10.0 | 6.5 | 1.75 | 31 bar (455 psi) | 65 mm |
| YN-PA6 1080 | 10.0 | 8.0 | 1 | 18 bar (265 psi) | 80 mm |
| YN-PA6 1280 | 12.0 | 8.0 | 2 | 22 bar (331 psi) | 70 mm |
| YN-PA6 1410 | 14.0 | 10.0 | 2 | 25 bar (363 psi) | 140 mm |
| YN-PA6 1612 | 16.0 | 12.0 | 2 | 22 bar (327 psi) | 160 mm |
| 1/8″ | 3.175 | 1.58 | 0.8 | 20 bar (290 psi) | 32 mm |
| 1/4″ | 6.35 | 4.35 | 1 | 14 bar (203 psi) | 65 mm |
| 3/8″ | 9.525 | 6.35 | 1.59 | 14 bar (203 psi) | 100 mm |
| 1/2″ | 12.70 | 9.60 | 1.55 | 10 bar (145 psi) | 130 mm |

## PA12 Nylon Tubing sizes (14 models)

Low-moisture-absorption nylon for stable dimensions in wet service and high-pressure circuits. Full details on the  [PA12 Nylon tubing page](<https://yuannaitube.com/products/pa12-nylon-tubing/>) .

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-PA12 0425 | 4.0 | 2.5 | 0.75 | 29 bar (426 psi) | 20 mm |
| YN-PA12 0640 | 6.0 | 4.0 | 1 | 27 bar (398 psi) | 30 mm |
| YN-PA12 0850 | 8.0 | 5.0 | 1.5 | 29 bar (426 psi) | 30 mm |
| YN-PA12 0855 | 8.0 | 5.5 | 1.25 | 19 bar (266 psi) | 45 mm |
| YN-PA12 0860 | 8.0 | 6.0 | 1 | 17 bar (256 psi) | 50 mm |
| YN-PA12 1065 | 10.0 | 6.5 | 1.75 | 24 bar (355 psi) | 80 mm |
| YN-PA12 1080 | 10.0 | 8.0 | 1 | 14 bar (213 psi) | 85 mm |
| YN-PA12 1280 | 12.0 | 8.0 | 2 | 16 bar (241 psi) | 93 mm |
| YN-PA12 1410 | 14.0 | 10.0 | 2 | 12 bar (174 psi) | 75 mm |
| YN-PA12 1612 | 16.0 | 12.0 | 2 | 14 bar (213 psi) | 95 mm |
| 1/8″ | 3.175 | 1.58 | 0.8 | 20 bar (290 psi) | 25 mm |
| 1/4″ | 6.350 | 4.35 | 1 | 14 bar (203 psi) | 30 mm |
| 3/8″ | 9.525 | 6.35 | 1.59 | 14 bar (203 psi) | 80 mm |
| 1/2″ | 12.70 | 9.60 | 1.55 | 10 bar (145 psi) | 125 mm |

## PE Tubing sizes (14 models)

The economical polyethylene range for low-to-medium pressure air and water lines. Full details on the  [PE tubing page](<https://yuannaitube.com/products/pe-tubing/>) .

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-PE 0425 | 4.0 | 2.5 | 0.75 | 6 bar (87 psi) | 20 mm |
| YN-PE 0640 | 6.0 | 4.0 | 1 | 6 bar (87 psi) | 30 mm |
| YN-PE 0850 | 8.0 | 5.0 | 1.5 | 7 bar (113 psi) | 40 mm |
| YN-PE 0855 | 8.0 | 5.5 | 1.25 | 5 bar (73 psi) | 45 mm |
| YN-PE 0860 | 8.0 | 6.0 | 1 | 6 bar (99 psi) | 50 mm |
| YN-PE 1065 | 10.0 | 6.5 | 1.75 | 6 bar (87 psi) | 50 mm |
| YN-PE 1080 | 10.0 | 8.0 | 1 | 4 bar (71 psi) | 75 mm |
| YN-PE 1280 | 12.0 | 8.0 | 2 | 5 bar (85 psi) | 60 mm |
| YN-PE 1410 | 14.0 | 10.0 | 2 | 5 bar (73 psi) | 80 mm |
| YN-PE 1612 | 16.0 | 12.0 | 2 | 3 bar (56 psi) | 110 mm |
| 1/8″ | 3.175 | 1.58 | 0.8 | 8 bar (116 psi) | 16 mm |
| 1/4″ | 6.35 | 4.35 | 1 | 5 bar (73 psi) | 35 mm |
| 3/8″ | 9.525 | 6.35 | 1.59 | 6 bar (87 psi) | 50 mm |
| 1/2″ | 12.70 | 9.60 | 1.55 | 4 bar (58 psi) | 80 mm |

## FEP Tubing sizes (14 models)

Fluoropolymer for chemical service and purity, transparent, rated 10–20 bar on metric sizes. Full details on the  [FEP tubing page](<https://yuannaitube.com/products/fep-tubing/>) .

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-FEP 0425 | 4.0 | 2.5 | 0.75 | 16 bar (224 psi) | 25 mm |
| YN-FEP 0640 | 6.0 | 4.0 | 1 | 17 bar (238 psi) | 40 mm |
| YN-FEP 0850 | 8.0 | 5.0 | 1.5 | 20 bar (280 psi) | 60 mm |
| YN-FEP 0855 | 8.0 | 5.5 | 1.25 | 20 bar (280 psi) | 65 mm |
| YN-FEP 0860 | 8.0 | 6.0 | 1 | 13 bar (182 psi) | 70 mm |
| YN-FEP 1065 | 10.0 | 6.5 | 1.75 | 19 bar (270 psi) | 80 mm |
| YN-FEP 1080 | 10.0 | 8.0 | 1 | 14 bar (196 psi) | 110 mm |
| YN-FEP 1280 | 12.0 | 8.0 | 2 | 18 bar (261 psi) | 100 mm |
| YN-FEP 1410 | 14.0 | 10.0 | 2 | 12 bar (168 psi) | 120 mm |
| YN-FEP 1612 | 16.0 | 12.0 | 2 | 10 bar (145 psi) | 160 mm |
| 1/8″ | 3.175 | 1.58 | 0.8 | 16 bar (232 psi) | 13 mm |
| 1/4″ | 6.350 | 4.35 | 1 | 10 bar (145 psi) | 50 mm |
| 3/8″ | 9.525 | 6.35 | 1.59 | 10 bar (145 psi) | 26 mm |
| 1/2″ | 12.70 | 9.60 | 1.55 | 6 bar (87 psi) | 130 mm |

## PFA Tubing sizes (14 models)

The premium fluoropolymer grade for higher temperature and high-purity lines. Full details on the  [PFA tubing page](<https://yuannaitube.com/products/pfa-tubing/>) .

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-PFA 0425 | 4.0 | 2.5 | 0.75 | 16 bar (224 psi) | 30 mm |
| YN-PFA 0640 | 6.0 | 4.0 | 1 | 17 bar (238 psi) | 36 mm |
| YN-PFA 0850 | 8.0 | 5.0 | 1.5 | 20 bar (280 psi) | 50 mm |
| YN-PFA 0855 | 8.0 | 5.5 | 1.25 | 20 bar (280 psi) | 55 mm |
| YN-PFA 0860 | 8.0 | 6.0 | 1 | 13 bar (182 psi) | 64 mm |
| YN-PFA 1065 | 10.0 | 6.5 | 1.75 | 19 bar (270 psi) | 80 mm |
| YN-PFA 1080 | 10.0 | 8.0 | 1 | 14 bar (196 psi) | 88 mm |
| YN-PFA 1280 | 12.0 | 8.0 | 2 | 18 bar (261 psi) | 72 mm |
| YN-PFA 1410 | 14.0 | 10.0 | 2 | 12 bar (168 psi) | 98 mm |
| YN-PFA 1612 | 16.0 | 12.0 | 2 | 10 bar (87 psi) | 128 mm |
| 1/8″ | 3.175 | 1.58 | 0.8 | 16 bar (232 psi) | 14 mm |
| 1/4″ | 6.350 | 4.35 | 1 | 10 bar (145 psi) | 37 mm |
| 3/8″ | 9.525 | 6.35 | 1.59 | 10 bar (145 psi) | 40 mm |
| 1/2″ | 12.70 | 9.60 | 1.55 | 6 bar (87 psi) | 100 mm |

## High-Pressure Composite Tubing sizes (28 models)

Two-layer reinforced construction in two variants, rated 12–19 bar with hose-like flexibility at small sizes. Full details on the  [high-pressure composite tubing page](<https://yuannaitube.com/products/high-pressure-composite-tubing/>) .

### V8 structure: PU outer layer + PA12 inner layer

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-0425 | 4.0 | 2.5 | 0.75 | 16 bar(242 psi) | 10 mm |
| YN-0640 | 6.0 | 4.0 | 1 | 14 bar(213 psi) | 15 mm |
| YN-0850 | 8.0 | 5.0 | 1.5 | 15 bar(228 psi) | 20 mm |
| YN-0855 | 8.0 | 5.5 | 1.25 | 12 bar(185 psi) | 20 mm |
| YN-0860 | 8.0 | 6.0 | 1 | 12 bar(185 psi) | 20 mm |
| YN-1065 | 10.0 | 6.5 | 1.75 | 19 bar(284 psi) | 25 mm |
| YN-1080 | 10.0 | 8.0 | 1 | 12 bar(185 psi) | 31 mm |
| YN-1280 | 12.0 | 8.0 | 2 | 17 bar(256 psi) | 35 mm |
| YN-1612 | 16.0 | 12.0 | 2 | 15 bar(228 psi) | 71 mm |
| 1/8 | 3.17 | 1.58 | 0.79 | 14 bar(196 psi) | 7 mm |
| 1/4 | 6.35 | 4.35 | 1 | 12 bar(168 psi) | 22 mm |
| 3/8 | 9.52 | 6.35 | 1.58 | 15 bar(228 psi) | 24 mm |
| 1/2 | 12.7 | 9.6 | 1.55 | 14 bar(196 psi) | 32 mm |
| 3/4 | 19.05 | 15.88 | 1.58 | 13 bar(213 psi) | 70 mm |

### V9 structure: polyether TPU outer layer + PA12 inner layer

| Model | OD (mm) | ID (mm) | Wall (mm) | Working pressure | Min. bend radius |
| --- | --- | --- | --- | --- | --- |
| YN-0425 | 4.0 | 2.5 | 0.75 | 16 bar(232 psi) | 16 mm |
| YN-0640 | 6.0 | 4.0 | 1 | 14 bar(203 psi) | 16 mm |
| YN-0850 | 8.0 | 5.0 | 1.5 | 15 bar(218 psi) | 29 mm |
| YN-0855 | 8.0 | 5.5 | 1.25 | 12 bar(174 psi) | 29 mm |
| YN-0860 | 8.0 | 6.0 | 1 | 12 bar(174 psi) | 29 mm |
| YN-1065 | 10.0 | 6.5 | 1.75 | 19 bar(276 psi) | 44 mm |
| YN-1080 | 10.0 | 8.0 | 1 | 12 bar(174 psi) | 30 mm |
| YN-1280 | 12.0 | 8.0 | 2 | 17 bar(247 psi) | 46 mm |
| YN-1612 | 16.0 | 12.0 | 2 | 15 bar(218 psi) | 70 mm |
| 1/8 | 3.17 | 1.58 | 0.79 | 15 bar(218 psi) | 8 mm |
| 1/4 | 6.35 | 4.35 | 1 | 14 bar(203psi) | 15 mm |
| 3/8 | 9.52 | 6.35 | 1.58 | 17 bar(247psi) | 25 mm |
| 1/2 | 12.7 | 9.6 | 1.55 | 15 bar(218psi) | 35 mm |
| 3/4 | 19.05 | 15.88 | 1.58 | 15 bar(218psi) | 75 mm |

## Nylon tubing in inch sizes: 1/8, 1/4, 3/8 and 1/2

Searching by fractional size? Our **nylon tubing** is listed in inch sizes as well as metric. The inch rows follow the nominal outside diameter (1/8″ is 3.175 mm OD, 1/4″ is 6.35 mm, 3/8″ is 9.525 mm and 1/2″ is 12.70 mm) with a tolerance of ±0.10 mm, and **working pressure** is quoted at 23°C. PA6 and PA12 are different materials, so read each column for its own material and compare the two only at the same size. See the  [PA6 nylon tubing page](<https://yuannaitube.com/products/pa6-nylon-tubing/>)  and the  [PA12 nylon tubing page](<https://yuannaitube.com/products/pa12-nylon-tubing/>)  for the full model tables, data sheets and ordering details.

| Nominal size | OD (mm) | ID (mm) | PA6 working pressure | PA12 working pressure |
| --- | --- | --- | --- | --- |
| 1/8″ | 3.175 | 1.58 | 20 bar (290 psi) | 20 bar (290 psi) |
| 1/4″ | 6.35 | 4.35 | 14 bar (203 psi) | 14 bar (203 psi) |
| 3/8″ | 9.525 | 6.35 | 14 bar (203 psi) | 14 bar (203 psi) |
| 1/2″ | 12.7 | 9.6 | 10 bar (145 psi) | 10 bar (145 psi) |

## Reading the patterns

Three patterns repeat across the chart and are worth knowing before you pick a row. First, pressure falls as diameter grows within a family, because pressure stress scales with diameter relative to wall. Second, at the same size the ratings differ sharply by material — a 8 × 5 tube runs from 7 bar in PU to 29 bar in PA6. Third, the smallest sizes carry the highest ratings everywhere: the 1/8″ tubes reach 8–20 bar depending on family.

## Same outside diameter, different bore: what changes

Two tubes can share an outside diameter and still deliver different circuits. The table below uses two hypothetical 8 mm tubes to show how the inside diameter drives the internal cross-section and the air volume the line holds.

| Dimension or calculation | Tube A | Tube B |
| --- | --- | --- |
| Outside diameter | 8 mm | 8 mm |
| Inside diameter | 5 mm | 6 mm |
| Wall thickness | 1.5 mm | 1.0 mm |
| Internal cross-sectional area | 19.6 mm² | 28.3 mm² |
| Internal volume per meter | 19.6 mL | 28.3 mL |

Source: geometric calculation, internal area = π × ID² ÷ 4 and volume = area × length. The dimensions are illustrative and are not model ratings or measured flow results.

Tube B has about 44% more internal cross-sectional area, but that does not mean 44% more airflow or a proportional gain in cylinder speed. Valves, fittings, supply pressure, exhaust path and tube length all affect response, and a thinner wall needs its own working-pressure check against the rows above.

Length matters as much as bore. Three meters of 6 mm ID tubing hold about 84.8 mL, against 28.3 mL for one meter. On a line that fills and exhausts every cycle, avoidable length adds volume, so shorten the route before assuming a larger diameter is the fix. When you order a replacement, write the size as OD × ID with units, because “8 mm tube” leaves the bore open.

## If your size is not in the chart

The chart lists standard production models. Custom inside and outside diameters, wall thicknesses and coil lengths are confirmed case by case: send the dimensions, quantity, medium, temperature range and **working pressure** through the  [quotation checklist](<https://yuannaitube.com/product-data-sheets/#inquiry-checklist>)  and we will confirm the feasible model and lead time. The full ranges sit on the  [product overview](<https://yuannaitube.com/products/>) , and the material-level trade-offs are on the  [industrial tubing materials page](<https://yuannaitube.com/industrial-tubing-materials/>) .

![Diameter readings displayed alongside a tubing production line](<https://yuannaitube.com/wp-content/uploads/2026/10/tubing-diameter-check-v1.webp>)

Fig. 1: Real-time outer diameter and wall thickness verification across standard extruded tubing batches.

## Tubing size chart FAQ

What sizes does industrial tubing come in?

Our standard range covers metric sizes from 4 mm to 16 mm outside diameter (model codes 0425 through 1612) and fractional sizes from 1/8″ to 1/2″, with 3/4″ additionally available in PU and high-pressure composite. Tolerance is ±0.10 mm on both diameters in every family.

Is tubing sized by OD or ID?

By both, plus the wall between them. A fitting accepts one specific OD-and-wall combination, so two tubes with the same OD but different walls are not interchangeable. The  [size and wall thickness guide](<https://yuannaitube.com/tubing-id-od-wall-thickness/>)  shows how to measure each figure.

Why do pressure ratings differ at the same size?

Material strength and construction differ: the same 8 × 5 size is rated from 7 bar (PU) to 29 bar (PA6) in the chart above. Use the material whose rating covers your **working pressure** at the actual **operating temperature**, with margin for cycling.

Are the model codes the same across materials?

Yes for the metric sizes: the four-digit code encodes the dimensions, so 0860 is 8 × 6 mm in every family, prefixed by material (YN-PU, YN-PUR, YN-PA6, YN-PA12, YN-PE, YN-FEP, YN-PFA). Only the rating and **bend radius** change with the material.

Can I order a size that is not listed?

Custom diameters, walls and coil lengths are confirmed case by case against quantity and application. Send the full requirement through the  [quotation checklist](<https://yuannaitube.com/product-data-sheets/#inquiry-checklist>)  rather than assuming from the chart.

**Next step.** Pick the family that covers your pressure and medium, open its product page for burst pressures and datasheets, or send the five items from the  [quotation checklist](<https://yuannaitube.com/product-data-sheets/#inquiry-checklist>)  for a confirmed offer.

## Frequently Asked Questions: Tubing Sizes & Dimensions

What are the most common pneumatic tubing sizes in industrial automation?

The three most widely used pneumatic sizes globally are: **6 × 4 mm** (the standard for solenoid valve pilot lines and compact cylinders), **8 × 5 mm or 8 × 5.5 mm** (for medium cylinders and air distribution manifolds), and **1/4″ OD (6.35 mm)** in North American machinery. For main air headers and heavy **pneumatic tools**, 10 mm and 12 mm OD lines are standard.

Why must tubing outside diameter (OD) have a tight tolerance for push-in fittings?

Push-to-connect (push-in) fittings rely on an internal stainless steel collet that bites into the tube OD, paired with an internal elastomeric O-ring that seals against the outer surface. If the tube OD is undersized by more than 0.10 mm, the O-ring cannot maintain adequate sealing pressure, causing micro-leaks. If oversized, insertion force becomes excessive and the collet can damage the wall. YUANNAI TUBE maintains strict ±0.05 mm to ±0.10 mm OD laser tolerances across all families.

How does tube inside diameter (ID) affect air tool performance?

Inside diameter determines cross-sectional flow area (proportional to ID squared) and dynamic pressure drop. Doubling the inside diameter from 4 mm to 8 mm increases volumetric air flow capacity by four-fold at the same supply pressure. For high-flow air motors or fast-cycling cylinders, choosing a thinner wall with a larger ID prevents sluggish cylinder speeds.

To match a size to a fitting, see  [push-in fittings and tubing](<https://yuannaitube.com/push-in-fittings-tubing-match/>) .

**Related guides:**  [pneumatic tubing guide](<https://yuannaitube.com/pneumatic-tubing-guide/>)  ·  [pneumatic tubing 6/4 and 8/6 mm](<https://yuannaitube.com/pneumatic-tubing-6-4-and-8-6-mm/>)  ·  [PU pipe and pneumatic pipe vs tubing](<https://yuannaitube.com/pu-pipe-pneumatic-pipe-vs-tubing/>) .

To see how much air a given size carries over your line length, use the  [compressed air flow calculator](<https://yuannaitube.com/compressed-air-flow-calculator/>) .

## Sources and scope

- [PA6 Nylon Tubing — English data sheet (v4-20261020)](<https://yuannaitube.com/wp-content/uploads/2026/10/yuannai-tube-pa6-nylon-technical-data-sheet-en-v4-20261020.pdf>)

- [PA12 Nylon Tubing — English data sheet (v5-20261020)](<https://yuannaitube.com/wp-content/uploads/2026/10/yuannai-tube-pa12-nylon-technical-data-sheet-en-v5-20261020.pdf>)

- [PU Tubing — English data sheet (v3-20261020)](<https://yuannaitube.com/wp-content/uploads/2026/10/yuannai-tube-pu-technical-data-sheet-en-v3-20261020.pdf>)

- [Polyether Tubing — English data sheet (v2-20261020)](<https://yuannaitube.com/wp-content/uploads/2026/10/yuannai-tube-polyether-tpu-technical-data-sheet-en-v2-20261020.pdf>)

Use these documents for the identified product models and stated test conditions. General material comparisons and selection checklists do not establish a different grade’s rating, fitting compatibility or project approval. Confirm the exact model, medium, temperature, pressure and required evidence before ordering.

Content review:  [zhangkexin](<https://www.linkedin.com/in/%E5%8F%AF%E6%AC%A3-%E5%BC%A0-14b6a7448/>)  · Marketing

Review scope: market information and document references.

## Tell us what your application needs.

Send your dimensions, operating conditions and quantity. Let’s identify the right tubing for your project.

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